Gold has been mined since ancient times. For the entire period while this activity is carried out in the world, the scale of production of this noble metal is approximately 170 tons. Half of the gold mined goes into the production of jewelry, which is quite expensive. According to scientists’ calculations, if all the mined gold is collected in one place, then it is possible to form a solid cube the height of a 9-story building with a 20-meter edge.

World gold mining

Nowadays, gold mining is not an exciting adventure that ruins some people and makes others rich. Now, this activity has become an actively developing type of income.

Enterprises that are engaged in industrial gold mining maintain accounting records, calculate economic feasibility, and conduct geological exploration using modern technologies. That is, it provides a workplace for many people with different professions.

Dozens of countries account for global gold mining, and the Russian Federation is no exception. Gold nuggets here are rarely found on the surface of the earth, however, at some depth underground, there are so many gold deposits that it allowed the Russian Federation to take fourth place in the production of this noble metal in the world. Today, Russia holds 7% of the world's total gold reserves.

The absolute leader in gold mining since the early eighties has been the Republic of South Africa, which provides about 70% of all gold production. Although, in the early nineties, South Africa's income fell by 35% due to a decrease in exploration of new gold deposits. And some states, such as Australia, on the contrary, have begun to increasingly develop underground and surface gold deposits located on its territory.

Methods of gold mining in Russia

Over time, gold mining methods have constantly improved and changed. At first, manual gold mining was widely used by sifting sand in water.

Then people mastered the extraction of noble metal from ore. These days, manual gold mining is a rarity. This process is mostly automated, but that doesn’t make it any easier. After all, to find a profitable deposit you need to spend a lot of effort and money. A payable deposit is considered to be one in which there are 3 grams of pure gold per 1 ton of soil.

More recently, a method called amalgamation has been popular in the gold mining industry. Its peculiarity lies in the use of a container placed at the bottom of the container. The barrel was filled with gold-bearing ore and shaken. As a result, gold particles remained in the mercury at the bottom of the barrel. The main negative quality of this method is the high toxicity of mercury.

Nowadays, gold is separated from ore using sodium cyanide. Thanks to the advent of this method, it became possible to extract gold from previously abandoned deposits, which returns their profitability.

Gold is also mined using dredges - surface-mounted mining machines equipped with everything necessary to extract metal from the ground. Dredging only works in areas with certain soil. This must be a watery area, so such special vehicles are often installed near river banks or other bodies of water.

What is a dredge?

A dredge is a device that is directly related to gold mining. The weight of this device reaches several hundred tons. This is a mechanized unit equipped with buckets operating on the principle of a chain excavator. On board the floating platform there is everything you need to wash rock and sand. A large dredge can be controlled by a crew of up to 10 people, while a small special vehicle requires only one manager.

The cost of dredging for gold mining is available only to large enterprises. Before installing this machine, you need to remember that this idea may be unprofitable if the content of precious metals in the soil is low.

Therefore, before using this special vehicle, it is necessary to carry out a number of reconnaissance activities, including geological research and chemical analysis of the soil composition to determine the concentration of noble metal in it. Only in this case will the profitability of industrial gold mining be justified. In addition, installing a dredge requires a lot of effort and time, since the machine is quite heavy and bulky.

Classification of dredges

Dredges are grouped:

• by the type of energy required for the operation of the device: electricity, energy from the combustion of gasoline or diesel fuel vapors;
• by depth of work with rocks below the water level: shallow-water, deep-water;
• by bucket capacity: small, medium, large;
• by maneuvering method: rope-pile, rope-anchor.

As a rule, two types of special machines are used for gold mining:

• marine;
• continental.

These types of dredges differ in that the marine special vehicle is similar to a ship that can be moved along the coast, while the continental one requires more resources, as it is mounted on a pontoon.

Smaller special vehicles called mini-dredges are ideal for individual gold miners or prospectors. They can either be purchased in special stores or made independently. The mini-drag has been significantly reduced in size. Its weight ranges from 25 to 100 kg.

A positive feature of using mini-dredges is that they reduce labor costs and speed up the gold mining process. Therefore, the interest of miners in constructing the unit with their own hands at home is justified.

Operating principle of the dredge

Externally, the mini-dredge looks like a vacuum cleaner that sucks up sand and gold dust in order to separate one from the other. All possible models of these special vehicles differ in size and materials from which they are assembled, but their structural elements are similar:

• a system that provides buoyancy of the device;
• drive responsible for the operation of the centrifugal pump;
• injector;
• washing chute for separating precious metal from slag;
• air supply system for breathing underwater.

Metal extraction using a mini-dredge is divided into 3 stages:

• pumping water under high pressure into the injector chamber;
• then water with sand and earth is sent to the washing trench to separate the noble metal from the slag;
• the drive starts the pump to sift out the gold in the trough.

The performance indicator for all devices is different, but on average it ranges from 100 to 1000 kilograms of processed rock per hour. Before you start working with a mini-dredge, you need to clear the bottom of the reservoir from stones, because they can clog the unit.

A miniature gold dredge is an effective and popular unit for gold mining. It is modernized over time and becomes more and more popular in prospecting circles. First, you need to seriously invest in the purchase or assembly of the device, but then this investment will bring considerable profit.

Before assembling homemade mini-dredges, you need to know that gold mining is prohibited in the Russian Federation. Along with this, artisanal mining of this precious metal is close to crime.

Video: Gold mining on a dredge

Gold is still the most expensive metal today. The relevance of its extraction has not changed over the past 100 years, only the methods have changed. Previously, these were enthusiastic gold miners with a tray in hand. Now they have been replaced by a dredge for gold mining - special industrial equipment.

What is dredge

A dredge is a mechanism for separating gold from the soil. Nowadays, it occupies a leading position among both individual and industrial gold miners as a means for washing precious metal. The reason for this lies in the simplicity of the design and at the same time the high performance of the dredge.

Features of the dredge

Not every deposit is suitable for gold dredging. Gold miners should take into account the following features:

• Healing gold is only possible in bodies of water: rivers, seas, etc. The dredge device is to blame (which we will look at in more detail below). The fact is that in water, rock particles weigh several times lower than in air. Accordingly, much less energy is required to lift them from the depths of rivers. When mining in open areas, it is necessary to significantly increase the power of the pump and electric motor, which is not practical due to the significant increase in the size and weight of the dredge.
• The need to conduct a study by geological services of the area for the presence of gold ore. The dredge itself does not have sensors and mechanisms for searching for gold. Its function is only to separate the metal from the ground. It is worth noting that today a deposit is considered profitable from a financial point of view if there are 3 grams of gold per 1 ton of rock.
• Not all types of soil are suitable for gold dredging. This refers more to the size of rock particles, rather than their chemical composition. The reason for this is the limitation of the size of the suction hoses through which soil is drawn from the bottom of reservoirs.

Dredge device

As mentioned earlier, the design of the dredge is not complicated.

Minimum electrics, maximum parts from a regular technical store. So, the following components of the dredge are distinguished:

1. Suction tip. In appearance it looks like a tapering cone. Made from thin sheet steel no more than 2 mm thick. The edges of the tip are fastened by manual arc welding. Different diameters of the cone bases are necessary to increase the suction area on the one hand, and on the other to more quickly transport soil to the surface of the water.
2. Supply hose. As a rule, it is represented by a high-pressure hose with a diameter of at least 12 centimeters. This size is due to the weight limitation of the dredge. To increase the rigidity and strength of the hose, a metal frame is embedded into its base.
3. Pressure hose. The same sleeve, but with a diameter of 50 millimeters. The main purpose of this unit is to supply clean water for washing and transporting gold with soil.
4. Pump. Provides direct pressure for supplying rinsing water. Not every pump is suitable for this. The most important parameter here is maintaining operability when large soil particles enter the working cavity. Various types of diaphragm, vane and gear pumps have proven themselves to be the best.
5. Electric motor. Necessary for transmitting torque to the pump. Typically, asynchronous three-phase motors are used, as they are the most convenient to operate. Their power depends on the performance of the installation. For a small-sized dredge, 2 hp is enough.
6. Flushing sluice. It is a curved container. The gateway serves as a place for screening gold particles from rocks. It is made from thin-sheet materials: steel and aluminum, in the case of a lightweight design.
7. Gutter A vessel where the deposited gold is directly collected.
8. Source of electricity. Required to supply electric current to the motor. This can be either a battery or a gasoline generator. In the case of large industrial scale mining, a power line is connected to the dredge.
9. Floating platform. Serves as a frame for installing all of the above equipment. Another function of the platform is to maintain the buoyancy of the dredge on the surface of the reservoir. Stability afloat is maintained by large tanks filled with air. The platform is made from structural materials. Most often this is aluminum.

Principle of operation

Gold ore particles are purified from rock in several stages:

• The electric motor turns on and the pump directs water into the pressure hose, thereby discharging the space between the river water and the suction tip.
• Due to the vacuum formed, the soil is drawn in by the suction nozzle and moves along the supply hose to the flushing sluice.
• Once there, the soil and water pass through a certain system of drops. The goal here is to separate the denser gold from the lighter rock particles.
• Then, after a certain time, the gold settles in the gutter, and the remaining soil is removed into the river along with the flushing water.

Before the actual start of the washing process, the dredge is adjusted to ensure the accuracy of catching the precious metal. This is done by adjusting the overflow differential, flow and pressure of the pump.

To ensure greater reliability of the correct operation of the dredge, a preliminary check is carried out, which consists of passing pieces of lead marked with paint through it. If, after passing through the sluice gate, painted metal is observed in the chute, then the dredge is working properly. If not, then it is sent for revision.

Classification of dredges

There are many types of gold dredges. They are divided according to the following parameters:

1. Power. This refers to the depth from which the dredge can remove soil. Typically, this value ranges from 5-50 meters.

2. Portability. There are stationary and floating dredges.

2.1. Stationary ones are powerful industrial dredges weighing up to 1,500 kg. In terms of their dimensions, they are comparable to 4-story modern houses. They have a large number of electronics and have greater ability to regulate the gold mining process. The management staff of such dredges consists of at least 10 people.

2.2. Floating - more mobile dredge models. They are significantly less in weight (40-150 kg) and power. Even 1 person can handle this dredge.

3. Screening performance. Depending on the type of pump, the diameter of the hoses and the type of flushing sluice, it can vary from 100 to 1000 kg of soil per hour.

Other mining methods

Extraction of gold from rocks is done not only by dredging. It is also worth noting the following methods:

• Manual. A gold miner extracts gold using a regular tray, washing the soil in it with water. This method was simple, but had very low productivity.
• Ore. Extraction is carried out in onshore deposits using special high-tech equipment: excavators, drills, etc.
• Hydraulic. The dredge mining method we are considering also applies to this. Gold is obtained by eroding rocks.

Rate this article:

This metal is driving humanity crazy

Before you start designing or purchasing equipment for gold mining, you need to take into account that as of November 2014, individuals and individual entrepreneurs do not have the right to officially search for and mine precious metals.

Although a law allowing such actions was considered back in 2011, it has not yet been adopted. Despite the bans, such activities are widely carried out in the North of Russia and Eastern Siberia, where people in the taiga extract gold from exhausted mines. The illegal production volume is about 10 tons, which is a tenth of the total Russian annual production.

You need more than just mining equipment

Gold mining can be carried out today by enterprises that have completed the appropriate package of documents and received all permits, primarily a license for the right to use subsoil. In addition, the gold mining enterprise must hire workers, provide mine development projects, mining and land allotment and equipment, among which the main place is dredging.

This mechanism is a mining machine that includes dredging, processing and other elements that allow you to remove waste rock, leaving precious metals. Dredges operate primarily in flooded deposits, with the exception of viscous clays, hard rocks and boulder soils. In order for the dredge to operate, a large volume of process water is required, so periodically the gold mining seasons in one corner or another of the globe are disrupted due to drought.

A machine for mining precious and other metals can be of marine or continental class. Marine options are built on the basis of keelboats that can move independently or under tow. They are engaged in development in deep lakes, oceans, and coastal zones. Continental ones are used on continents and are formed on the basis of a pontoon, a flat-bottomed vessel.

Dredges can run on electric power, a combination of electricity and diesel, diesel and even steam. They can take soil from depths from 6 to 50 meters below the waterline, scoop soil with either one bucket or an entire bucket chain. Based on the size of the buckets, combine harvesters are divided into small (up to 100 liters) and large (about 250 liters). If the dredge operates in the open sea, then it moves on an anchor-rope device. Such equipment is extremely bulky and costs a lot of money.

Do-it-yourself flushing device for mining

This is what this device looks like

Therefore, discussions continue among amateur techies about whether a mini-drag can be made with your own hands. Masters believe that theoretically it can. To make it, a frame is made from lightweight materials (often aluminum sheets from a landfill), to which truck tires are attached to ensure the structure's buoyancy. If there is a desire for the design to be more reliable, then a plastic pontoon is taken as a basis, including collapsible structures. This option will be more expensive and much heavier. In addition, the frame can be mounted on plastic barrels with a volume of about 40 liters.

A motor, a water pump, an air compressor, hoses, and a flushing chute are mounted on the frame. Some craftsmen in the West make the latter on their own, based on their own preferences in gold mining (many countries allow work for private individuals). Many gutters are based on the “Hungarian effect”, when water after the next threshold forms a waterfall and does not foam much (so as not to lose metal elements). They are made of steel, welded together into a lattice and mounted on a specially bent aluminum sheet, which is the gateway. All elements of the gutter must be lined with so-called prospector moss, which is a vinyl covering resembling spaghetti in pattern. Particles of precious metals are retained in it.

Western prospectors engaged in individual mining call the preferred hose size a diameter of about 10-12 cm. Such a hose is convenient to operate alone during washing, while a diameter of 14 cm already provides more than significant physical stress, which not everyone can withstand.

The flushing process assumes that the socket from the dredge will be installed in the head of the sluice so that flows of water with soil enter it, which is washed, and the remainder is discharged into the water behind the mini-dredge. Water must enter the pump through the suction valve, without sand, since the presence of grains of sand can lead to damage to the pump. Therefore, an amateur dredge cannot work without a valve. An elevator with a suction nozzle is installed at the end of the hose.

Video on minidrags:

Today we will talk about how to pan or mine gold yourself using a mini-dredge. We will also learn how to make a mini-dredge for extracting gold from rivers and streams with your own hands from scrap materials. Let's look at assembly methods, diagrams, drawings and photos of homemade mini dredges for washing gold

A standard homemade simple mini-drag with a bottom ejector, a hopper, pontoons, a frame, a motor/pump of approximately 2.5 hp, and includes:

1. Hopper with a rumble;
2. Gateway 25x90 cm;
3. Inflatable pontoons;
4. Frame;
5. Bottom ejector of the jet pump;
6. Adjustable supports and fastening elements;
7. Water intake suction hose;
8. 2-inch working hose 5 or 6 m;
9.Soft hose-sleeve 8m. for irrigation of the bunker;
10. High pressure hose with a diameter of 1.25” and a length of 1.5 m
Dimensions of this dredge: 130x60x40 cm.
fuel consumption 0.7 l/h
Productivity: from 1 to 1.5 cubic meters/hour.

Self-made suction-type mini-dredges (dredges) are known, containing a pontoon, a superstructure and a power plant. To facilitate soil enrichment, the latter and water are transported via a floating pipeline to the shore.

Known devices are very ineffective due to the need to create pressure transport of the pulp; acquisition and operation of a floating pipeline; high costs for storing tailings from a stationary processing plant.

The closest in terms of the totality of essential features is a mini-dredge with a scoop capacity of 50 liters, containing a pontoon, a superstructure, a power plant, a screen, fine filling sluices and a pebble tray. However, with a relatively high productivity, the dredge has significant dimensions for the development of small deposits, high metal and energy consumption, requires significant installation and dismantling costs, and is difficult to operate.
The main objective of the invention is to create a mini-dredge that can reduce metal consumption, energy intensity and installation costs, as well as increase the efficiency of classification and disintegration of clayey sands.

To solve the problem, a mini-dredge consisting of a pontoon, a superstructure, a power plant, a screen, shallow-filling sluices and a pebble tray, additionally contains a deep-filling sluice located above the bow of the dredge in front of the grate screen, mounted on the superstructure with the possibility of oscillation and rigidly connected with a power plant.

The screen is equipped with removable grates of the grate type, with the lower edge of the upper grates mounted on the upper edge of the lower ones.

In relation to the prototype, the claimed invention contains the following features: the mini-dredge is additionally equipped with a deep filling sluice located above the bow of the dredge, in front of the grate screen, mounted on a superstructure with the possibility of oscillation and rigidly connected to the power plant. The screen is equipped with removable grates of the grate type, with the lower edge of the upper grates mounted on the upper edge of the lower ones.

The additional installation of a deep filling sluice on the dredge above its bow in front of the grate screen reduces the length of the dredge and, accordingly, its metal consumption.

The screen, installed on a superstructure with the possibility of oscillation, makes it possible to increase the efficiency of classification and disintegration of metal-bearing sands due to oscillations of the screen box.

Removable grate type screens make it possible to periodically clean them by one person without the use of special devices such as a crane beam, which reduces the size and weight of the dredge and, accordingly, its metal consumption and specific energy consumption.

The arrangement of grate type grates along the pulp flow in such a way that the lower edge of the upper grates is installed on the upper edge of the lower grates ensures effective unloading of the grates from large soil particles, which makes it possible to increase the efficiency of classification and disintegration of clayey sands.

The essence of the invention is illustrated in the drawing, which shows a general cross-sectional view of the mini-dredge.

The mini-drag includes a pontoon 1 with a power unit 2, a soil intake device 3, a soil pump 4, which is connected through a pipe 5 to a deep filling sluice 6, rigidly mounted on a superstructure 7 in front of a screen 8 with removable grates 9 of the grate type. The screen 8 is mounted on a superstructure 7 with the possibility of springs 10 oscillating and a rigid connection 11 with the power unit 3.

Directly under the screen 8 there is a distribution device 12 and sluices for fine filling 13, and at the end there is a pebble tray 14 and a stacker 15.

The mini-dredge works as follows: soil deposits with useful components are loosened by a rotary or milling type excavation device and enter the soil intake device 3 due to the operation of the soil pump 4 driven by the power unit 2 (electric motor or diesel engine). Water with ground deposits (pulp) comes out under pressure from the soil pump 4 and through the pressure pipe 5 enters the deep filling sluice 6, where large grains of useful components are captured.

Next, the pulp enters the screen 8 onto removable gratings 9 of the grate type, where the classification of soil deposits by size occurs, and the efficiency of screening is also ensured by the vibrations of the screen box under the influence of vibration of the power unit 2 and the soil pump 4 due to the installation of the box on the superstructure 7 using a spring 10 and a rigid connection with the power plant 2. Then, with the content of soil particles, it enters the distribution device 12, and then onto the fine filling gates 13 to trap small grains of the useful component. Large soil particles from the screen enter the pebble tray 14 and are removed by a stacker 15 into the pebble dumps.

Thus, the proposed mini-dredge, in comparison with the prototype, makes it possible to reduce its metal consumption by 2.5-3 times, specific energy consumption, as well as the costs and time for installation (dismantling) of the dredge from 250 to 2 days.

Many prospectors would like to have such a wonderful gold mining device as their own suction dredge, but the prices for this equipment, unfortunately, are high. However, we should not forget that at the dawn of dredging, there were no factories producing dredges, and these small devices were assembled by hand in some garage. So if you make it yourself, you will save a lot of money, just like I did.

Of course, you will use everything that is cheapest, but do not count too much on the fact that you will get by with a symbolic amount. No one wants everything on their drag to be wobbly, falling apart, or not working. The device must be functional, reliable and durable. You will not waste your time thinking about your project and deciding what to do and how to do it. Think about what exactly you want to get in the end and what you need, weigh everything together and decide what you can afford. Make diagrams and lists. Perhaps the best thing I can advise you in this case is to study the design of devices from such well-known brands as Keene and Pro-line. These companies have done extensive research on their equipment, tested various settings, and improved the components of their dredges so that they perform excellently.

By visiting the websites of the above-mentioned companies, you will find excellent photos of these devices and view information about the components from which they are made. If your local prospecting store sells ready-made dredges, examine them carefully, perhaps even take some measurements and, if possible, take photographs. Another great opportunity is to join a prospecting club whose members are active in dredging. It won't hurt you if you watch them at work. Members of such a club may even allow you to stand behind the dredge yourself. The more general knowledge you have about dredging, the better your design will be.

If you find a landfill or recycling plant, then you can get some important parts at the lowest prices. I advise you to take a list of the necessary components and materials and visit such a place with it. There you can even find the right engine for your dredge.

When you finally get around to building your own dredge, the first question that will probably arise is how big you want to build it. The larger the dredge, the more soil it can process, but the greater its weight and cost. You must find a compromise between these values, focusing on the volume of material being processed and the possible depth at which you will dredge.
Another aspect that is worth thinking about is that you are better off building a dredge with a hose diameter of 10 - 12 centimeters, that is, it should be of such a size that you alone can handle it. Although, if you are a young, tall strongman, you may be able to carry a 14-centimeter device, but this will take a lot of effort and time. 10 centimeters is perhaps the best size for equipment operated by one person.

Do you need compressed air for diving? Then you will need an air compressor, an air intake tank, and also diving equipment. Air is a really handy thing, but it's not at all necessary: ​​you can always do it later if your project is good and you're planning on installing a compressor on your dredge.

To build your dredge you will need a motor and a pump, as well as various tools, such as a hacksaw, riveting hammer, screwdrivers, wrenches, etc. The more experience you have in this type of work, the better your dredge will turn out. Knowing how to use a welder is also very important, as my little 120 volt welder has helped me solve some pretty tricky problems during the build process. If you don’t have such a device, then this is another reason to buy it! I highly recommend you have a welding machine.

Pay close attention to the price of the parts and decide what you can afford: you, of course, can save a lot of money by assembling the dredge yourself, but you will still have to spend money. I strongly recommend that you calculate the expected costs before you start purchasing the necessary components. Make sure you have enough money for everything. As for me, I decided to purchase some parts from Keene because I don't think I can make them any better than that company. On the other hand, I also bought some used components.

Everything I used to build my 10cm dredge cost about a third of what it would cost to buy a new one.

Almost impossible to do yourself (but you can buy used)

Engine

I've seen really good homemade dredges, but no one has installed homemade engines on them as well. You can buy a used motor and save some money, but no one makes this part themselves. Make sure your engine has the correct holes to attach the pump to it. Select its size according to the pump size. Manufacturers use specific dimensions for these components, as well as the dimensions of the hose used. Focus on them.

Water pump

Like I said, I've seen some really great homemade suction dredges, but again, no one has installed homemade pumps on them. A centrifugal pump, used by all dredge manufacturers, is the best choice. I recommend that you purchase a pump from Keene. I bought mine used at a local goldsmith's shop. Do not use a slurry pump: the large volume of sand and gravel that will flow through it will quickly damage this part. They are also quite heavy and will require a larger motor.

Air compressor

I have a compressed air pump but haven't installed it on my dredge. I have been dredging for many years, but have never used anything other than a snorkel, although of course this imposes its limitations on the choice of bodies of water for work. In this case, if you have long arms, you are truly lucky. If you do have a compressor, make sure it can be connected to the motor. Do not use pumps or hoses that are not designed to produce breathing air.

There are many options when choosing a hose, but be careful: the thin and fragile materials from which this part may be made will wear out quickly. The transparency of the hose is also important - you can see where it is clogged. The materials used by dredge manufacturers are excellent: they are reliable and will allow you to successfully dredge.

Ore washing chute (sluice)

The gateway is perhaps the biggest and most important thing you can do on your own. This is the key and most important detail - if your gateway doesn't capture the gold, the whole project will go down the drain.

I have used a homemade 4-inch dredge for many years in various California fields. In order for the device to suck in more rock, some time ago I replaced the old pump with a new, more powerful one. However, as I continued my work, I noticed a decrease in the share of fine gold being mined. I knew that old-fashioned sluices were not very good at catching small metal particles, and increasing the amount of material fed further reduced the recovery rate.

One day in 2002, while working on a dredge, I noticed a small nugget move too far down the sluice, almost falling out of it. Its weight was 8 grains. Thus, I realized that I needed to do something to prevent gold from being lost in the process. I began to think about this problem. Driven mainly by high prices, I decided to build my own gateway. I didn't have a specific plan or plan, but being a mining engineer by training, I have access to the equipment needed in this case, so my project did not seem impossible.
The design of almost all portable gateways is based on the so-called “Hungarian” stencil, which I wanted to install for myself.

The idea of ​​the “Hungarian” (also called LazyL) stencil is as follows: water and rock flow through the stencil, and behind each threshold a small waterfall is formed. Light particles pass on, and heavy particles, such as gold, are deposited. There is nothing technically complicated here: the thresholds are made from a piece of steel. All this can be done independently. These steel thresholds are much more effective than any other. When considering my own gateway, I carefully examined similar equipment in the nearest prospecting store, and also visited the GPAA Gold Prospectors exhibition, where I paid special attention to Keene gateways.

I decided that a gateway equipped with such a stencil is the best choice for me and with the help of such a device I will extract all the small gold that is possible. Keene uses this design on its latest drag models. But first, I had to get a bell (a device for feeding rock to the sluice). However, it is very difficult to make, so I purchased a bell from Keene. They are made of molded plastic, and this is the main reason to buy and not make it yourself. When I purchased the bell for my project, I expected the piece to fit a 16-inch (40 cm) wide sluice.

My old sluice was 53 inches (132 cm) long, and the new one had to fit the existing frame (I didn't want to remake it). I spent a couple of days scouring the surrounding landfills, looking for anything useful. My entire project was based partly on what I already knew about the operation of similar equipment, partly on what I saw in commercial samples, and partly on what I was able to find in junkyards or what I had lying around in my garage.

The more time you spend thinking about the design of your future DIY gateway, the better. Of course, you don’t really want to buy any unnecessary parts, but at the same time, the device must be effective. A good work plan and understanding of the gold mining process itself are very important. Prospector's moss, which is not used on commercial equipment, is, in my opinion, a very important detail in the design of the gateway. I laid it under all the thresholds of my device.

In a three-section lock, most of the gold is collected at the top. When the pebbles pass further, they are caught on a screen with 5mm holes (on my sluice). Then, the remaining pebbles and tiny gold pass to the bottom of the sluice. There, the slower speed of the water allows small metal particles to settle. Material larger than the holes on the screen goes into an additional section of sills before finally exiting the sluice. This is a common device of similar equipment

I borrowed metal shears and a press brake from a friend of mine. I cut the steel into strips and bent them into sills. They looked like standard Keene gateway parts, modified in the Hungarian way. To make the sills, I secured the edge of a strip of steel about a quarter inch and bent the rest at a 45 degree angle. If you have a press brake, then doing all this is not a problem at all. The thresholds of the upper section are 18 mm high, the next one is 30 mm high, and the lower one is 9 mm high. I used standard 1.5mm mild steel for all sections. The airlock itself is a large piece of bent aluminum. You can do it in two hours.

A project like mine requires special tools such as tin snips, a press brake, and welding equipment. It is impossible to do without it. Once you have cut and bent the steel the way you want it, the next step is to weld everything. In order to mount the thresholds, welding will also be required. There's nothing complicated about it. I'm not the best welder, however, and I managed to make everything strong and secure.

In order to secure flat strips of steel in the right place, they are welded at the ends of the thresholds. The straight part of the threshold is welded at a right angle to the bottom of the gateway, and the bent part at an angle of 45 degrees.

For people with the right tools and some metalworking skills, making such a gateway is not the most difficult thing. I spent about 10 hours on all this. The gateway took much longer to plan and design.

Modification of floating frame

In order to use the frame I already had, I had to make some modifications to it, namely raising the engine a couple of inches and accommodating a bell that runs underneath. I have truck tire tubes on my frame.

The frame itself is quite wide, but there is no difficulty in trimming it if necessary.

Exploitation

When I first started, I noticed a big difference between the performance of my new gateway and the old one. The light water no longer foamed on it, but flowed very well and correctly. When I first scraped, I found that fine gold was much better recovered. In general, the gateway did what was required of it. I've never had problems with sections overloading, although it does happen to those using Keene equipment. I lengthened the section where the 3/8″ sills were installed a bit and noticed that the slope was not enough and the water was carrying up large particles of pebbles. After I removed this part, it seemed to me that the device still worked great, although perhaps the removal would have been increased with the missing section. Next year I'll shorten it a bit and try again.

Work report

When I cleaned the lower sections of the sills, I noticed that along with the "black" sand, there was only fine gold left there. According to Keene's advertising, their equipment deposits 90 percent of the visible gold in the first section, which means my gateway performs about the same. A small amount of gold was found behind the thresholds of the upper section, so I placed prospector's moss there. The first cleaning showed a significant increase in gold recovery. Even more than I expected.

In my opinion, the main thing to do to improve extraction is to get rid of the junction box. The bell slows down the flow and distributes the material, thereby increasing production volume. Just compare the fact that all the light water is bubbling and foaming in the box of my old sluice with the work of the new version of this equipment.

The design of the gateway held up well, only once during the work process did a piece of welding break, which, however, did not affect the functioning in any way.

For those who are interested in making their own gateway, I can say that with metal working skills, it is quite easy to do. If you are making a gateway, into which the material must be fed with a shovel, then, in this case, the design of the device will be even simpler.

Building a homemade gold mining sluice, in my opinion, is a great start for a beginner. You just need to carefully study commercial copies, and then develop your own project.

On the other hand, if you are making a sluice for a dredge, I recommend making it two levels. These install Keene and Proline on the latest models of their drags. I don't have ready-made drawings, but you can draw them yourself, it's not difficult, just look at your friend's gateway or the one they sell at your local prospecting store. Be sure to use prospector moss, placing it under the thresholds. This detail will significantly increase the ability to “catch” gold.

Here is an estimate of my costs for creating a gateway:

Aluminum pieces $10

Iron pieces $5

Paint $4

Prospector's moss $56

Welding Rods $8

Total $83.

I think a new dredge sluice of the same size would cost over $500. The funny thing is that I spent the most money on prospector's moss. I actually think it improves gold recovery. This is perhaps the second most important detail after the bell and increases the production of fine gold.

The remaining elements of the dredge are described below.

Bell (water collector, distribution box)

It is installed at the head of the sluice and serves to direct the flow of water and soil into it. Here you need to make a decision. You can make it quite easily. Personally, I splurged and bought this part from the same Keene company.

It is quite difficult to make, but if you have welding skills, it is possible. First, you need to determine whether you will use a suction nozzle or a suction nozzle on your dredge.

The suction tip (nozzle) has been used since the first jet dredges were introduced. Its essence lies in the fact that the suction device (hydraulic elevator) is placed at the end of the supply hose (Fig. 2). In this case, a stream of water from the pump is supplied to its beginning through a nozzle and a vacuum is created here. The main inconvenience of this scheme is the need to have two long hoses, one from the pump to the nozzle, and the other for feeding the rock. It is difficult to control a suction nozzle with two hoses attached to it, especially on large dredges. Therefore, the tip is used only on small dredges when working in shallow water. The suction tip works more reliably in shallow water than the nozzle.

The suction nozzle is distinguished by the fact that the device that creates the vacuum is adjacent directly to the receiving box of the flushing sluice. In addition to more convenient control of the suction hose when extracting soil, this design has a number of other advantages. Considering the proximity of the power unit (engine and pump) to the nozzle, it becomes possible to install two, three or more pumps with separate pipes, which significantly increases the performance of the dredge with the same diameter of the suction hose.

In addition, the short length of the pump hose to the nozzle leads to significant pressure stabilization, and, consequently, to greater stability of the entire system as a whole. At the same time, when working in shallow water, air may enter the suction hose, and the rock supply will stop until the hose is completely filled with water. Therefore, in shallow water the nozzle is less effective and a suction nozzle is preferred.

Providing buoyancy

At this stage of creating a dredge you can save a lot. You can ensure the buoyancy of your device in a variety of ways. At the very beginning of the history of the use of dredges, large tires from trucks, which weigh little and are inexpensive, were used for this purpose. This is the option I chose for my own model, but I quickly discovered that getting such tires is becoming more and more difficult.

Today, manufacturers install plastic pontoons on most dredges. They are more reliable, but at the same time, heavier. There are many options here too. On some home-assembled dredges I have seen a variety of types of these plastic pontoons. An interesting way is to use plastic containers or barrels (capacity 20 - 40 liters). They can be bought quite cheaply. You can, of course, purchase pontoons from a specialized drag manufacturer, but this will cost a pretty penny.

Another important part of the buoyancy system is the frame on which the ore chute and motor are mounted. I made it from pieces of aluminum found in a landfill. All this was very cheap and did not require much effort. Since the frame was flat, I easily attached truck tires to it.

Checking dredge operation

Once you have found all the necessary parts and assembled the dredge, it is time to check how it works. To do this, take a couple dozen small pieces of lead, line them up and paint them with a bright paint, such as red. Take some soil from the nearest body of water and place the lead there. Test your dredge on this soil by washing the rock, removing the concentrate from the sluice and counting how many pieces of metal you extracted. Losses should be no more than 1-2 pieces. If, unfortunately, it happens that more lead is missing from the gutter than is written above, you need to adjust the dredge, make the necessary improvements until you are sure of its good work.

Finally, you will need a specific type of diving suit depending on where you will be using the dredge. Even in California in the middle of summer, after two hours of being in the water, it gets damn cold, so this kind of protection is a must.

Most of the previously explored gold deposits along rivers and streams, especially in the pre-revolutionary period, are currently abandoned and have not been developed for a long time, but in vain. In fact, their potential is far from exhausted.

In those distant times, compared to modern methods, the gold mining technique was primitive and more than 50% of the gold remained in dumps or was simply not discovered. If you walk through an old mine these days, even with an ordinary metal detector or mini-drag, you can already collect a decent gold “harvest” on the first day.

You just need to know where such an abandoned mine or gold deposit is located. Old pre-revolutionary maps of gold deposits, detailed geological and topographic maps of exploration of gold ores, veins and placers can help with this. As a rule, such maps are not freely available. They can be found in regional archives or large libraries.

The process of gold mining today is practically no different from the first methods of searching for the precious metal. As before, ingots are searched for in mines or along river banks. But modern technology has made the process itself much simpler and easier.

There is no longer a need for mine managers to hire large numbers of people to work. Several people can handle the task with the help of special equipment.

A dredge is a machine for washing gold. The complex structure of the unit consists of several components, each of which performs specific functions:

• Digging and scooping the earth. A powerful bucket can daily handle at least a ton of earth per day. This replaces 12,000 workers, which significantly saves not only human resources, but also time.
• The land is enriched in the process of work. This is of great importance from an environmental point of view.
• The machine independently selects pieces of gold from the soil, and after processing the soil itself is sent to its original place. There is no longer any need to manually filter or control this stage.

Due to its heavy weight and high cost, only large entrepreneurs can purchase a dredge.

Before purchasing, it is very important to analyze the amount of precious metal in the places for which the dredge is purchased. Since there may be relatively little gold in the soil, purchasing a dredge will simply be unprofitable.

The area where the dredge will operate must have soil with high humidity. Therefore, the optimal areas for installing the unit are coastal areas of rivers or lakes.

Installing a dredge is a very labor-intensive process due to the heavy weight of the machine. As a rule, two types of products are most widely used:

1. which moves through the water along the shore. In appearance it resembles a swimming vessel.
2. Continental Dredge. Its purchase and installation are very expensive, since the basis for such a machine is a pontoon.

The operating principle of a dredge for gold mining technology is similar to a vacuum cleaner: the sucked soil is processed, filtered and enriched. Thanks to high-quality filters, the dredge can retain even the smallest gold particles.

The dredge is filled with diesel fuel. Certain types of machines run on electricity or steam. The scoop reaches a depth of 50 meters, which makes it possible to thoroughly examine the soil for the presence of precious metal.

The main advantage of the dredge is that it greatly simplifies production. After all, one machine can replace hundreds and even thousands of people.

It was in this regard that prospectors were puzzled by a new pressing question: how to make mini-dredges for gold mining with their own hands.

It is important to remember that gold should be mined only on the basis of the appropriate permit and a special license to carry out such work. Otherwise, the violator faces not only administrative, but also criminal liability.

A self-made machine for searching and mining gold is a simplified technology and is called a mini dredge. Its design is simple, and the main materials are plastic or aluminum.

To improve the buoyancy of the dredge, car tires are attached to it. An analogue could be plastic barrels. In addition, the components of the device include:

Checking a homemade machine is carried out using labeled lead. If it is returned to the owner in full, then the machine can be used for gold mining.

It is very important to understand that you can only use your unit in a legal way. Everything must be legislated.

The desire to get easy money has never gone unpunished. Due to the proven effectiveness of mini-drags, more and more people are trying to make such a machine themselves.